Models are simplified representations of of different complex systems. They also help to study very small or large objects.
Option B, D and E.
Explanation:
Models are very simplified representations of complex systems and organs or structures which are prepared to study those systems by scientists and normal people easily. Many structures of human body like cells or some tissues are very small in structure or microscopic in nature. So studying them are very hard without specific instruments which are not always available. Thus models are made to easily study those structures by scientists and even normal people and students.
The correct answer is: E) provide the defense for the CNS
Astrocytes are star-shaped cells found in central nervous system (brain and spinal cord) .Some of their functions include:
• Support of neurons by supporting endothelilal cell of blood–brain barrier,
• Provide nutrients to neurons
• Maintain ion balance and thus controlchemical environment around neurons
• Repair of injuries in the brain
• the secretion or absorption of neural transmitters…
The cells that provide the defense for the CNS are called microglia. Those cells are also glial cells, derived from macrophages and thus, part of active immune defense.
Answer:
Since sexual reproduction requires two individuals, it allows intermingling of genes which is beneficial for the individuals as well as the entire species. The organisms produced by asexual reproduction are genetically identical to each other. ( I hope it helps )
Answer:
areas of high pressure to areas of low pressure
